Aspects of this disclosure are generally related to data storage systems which can be used to maintain relatively large data sets and support a relatively large number of concurrent users. The basic building blocks of a scalable data storage system may include storage engines or storage servers. A plurality of storage engines or storage servers are interconnected in order to function together as a storage array or storage server cluster. Additional storage engines or servers may be added to increase capabilities of the data storage system. Each storage array or storage server cluster typically includes multiple physical storage devices which are used to present logical storage devices to instances of applications running on host devices. A wide variety of technologies can be used to interconnect storage engines and storage servers, including but not limited to Infiniband, PCI-X, Fibre Channel, Gigabit Ethernet, and various proprietary technologies.